EXCHANGE 


Hbe  TIlnix>ersitE  of  (Ibicago 


Mercuri-Organic  Derivatives 

L     The  Mercurization  of  Aromatic  Amines  and 
Its  Relation  to  the  Theory  of  Substitution. 

IL   A  Study  of  the  Nitranilines.     Determination 
of  the  Position  of  the  Mercury  in  the 
Mercurized  Nitranilines. 

A  DISSERTATION 

SUBMITTED  TO  THE  FACULTY 

OF  THE  OGDEN  GRADUATE  SCHOOL  OF  SCIENCE 

IN  CANDIDACY  FOR  THE  DEGREE  OF 

DOCTOR  OF  PHILOSOPHY 


DEPARTMENT  OF  CHEMISTRY 


BY 


ISADORE  MEYER  JACOBSOHN 


Private  Edition  Distributed  by 

THE  UNIVERSITY  OF  CHICAGO  LIBRARIES 

CHICAGO,  ILLINOIS 

1922 


Reprinted  from  the  Journal  of  the  American  Chemical  Society,  Vol.  XUII.  No. 
-    August,  1921  and  Vol.  XUV,  No.  4,  April,  1922. 


Zlbe  lUntYJersits  of 


Mercuri-Organic  Derivatives 

L     The  Mercurization  of  Aromatic  Amines  and 
Its  Relation  to  the  Theory  of  Substitution. 

II*   A  Study  of  the  Nitranilines*     Determination 
of  the  Position  of  the  Mercury  in  the 
Mercurized  Nitranilines. 

A  DISSERTATION 

SUBMITTED  TO  THE  FACULTY 

OF  THE  OGDEN  GRADUATE  SCHOOL  OF  SCIENCE 

IN  CANDIDACY  FOR-  THE  DEGREE  OF 

DOCTOR  OF  PHILOSOPHY 


DEPARTMENT  OF  CHEMISTRY 


BY 

ISADORB  MEYER  JACOBSOHN 


Private  Edition  Distributed  by 

THE  UNIVERSITY  OF  CHICAGO  LIBRARIES 

CHICAGO,  ILLINOIS 

1922 


Reprinted  from  the  Journal  of  the  American  Chemical  Society,  Vol.  XLIII,  No.  8, 
August,  1921  and  Vol.  XLIV,  No.  4,  April,  1922. 


MERCURI-ORGANIC  DERIVATIVES.     THE  MERCURIZATION  OF 

AROMATIC  AMINES  AND  ITS  RELATION  TO  THE  THEORY 

OF  SUBSTITUTION.1 

The  principles  underlying  the  mercurization  of  aromatic  compounds 
have  occupied  the  attention  of  one  of  us  (Kh.)  for  the  past  two  years. 
The  important  fact  that,  in  a  mono-substituted  benzene  derivative,  the 
mercury  enters  para  or  ortho  to  the  group  already  present  in  the  molecule, 
was  pointed  out  early  by  Dimroth,2  and  has  been  substantiated  by  the 
vast  amount  of  experimental  work  done  by  others.  This  fact  of  ortho 
and  para  substitution  is  particularly  striking  when  one  attempts  to  apply 
the  theories  of  substitution  to  mercurization  since  mercury  never  enters 
meta  to  the  group  already  present  in  the  molecule.  Even  where  the 
usual  rules  of  substitution  require  that  a  rneta  derivative  be  formed, 
e.  g.,  with  benzoic  acid,  benzophenone,  and  nitrobenzene,  only  ortho  sub- 
stituted mercury  compounds  have  been  isolated. 

The  phenomenon  of  mercurization  was  considered  by  Dimroth  to  be 
similar  to  that  of  nitration,  sulfonation,  etc.,  in  the  sense  that  the  po- 
sition taken  by  the  entering  mercury  in  compounds  containing  groups  now 
considered  electro-negative,  e.  g.,  amino  or  hydroxyl  groups,  was  quite 
in  agreement  with  the  rule  of  Crum  Brown  and  Gibson.  He  considered 
the  exceptional  behavior  of  nitrobenzene,  benzoic  acid,  and  benzophenone 
as  anomalous  reactions  which  needed  to  be  accounted  for.  However, 
until  recently,  no  effort  has  been  made  to  explain  the  orientation  of  mer- 
cury in  the  benzene  molecule.3  The  rule  of  Crum  Brown  and  Gibson, 
being  purely  empirical,  offers  no  suggestion  as  to  the  mechanism  of  the 
reaction,  nor  does  it  help  to  predict  whether  a  compound  could  be  mercur- 
ized  or  not.  Therefore,  it  appeared  desirable  to  apply  some  of  the  mod- 
ern theories  of  substitution  to  the  orientation  of  mercury  in  the  benzene 
molecule. 

In  the  present  paper,  the  authors  will  confine  themselves  to  the  mechan- 
ism of  mercurization  of  aromatic  amines  and  also  attempt  to  show  that  the 
mechanism  suggested  for  mercurization  may  be  extended  to  explain  sat- 

1  This  work  was  carried  out  in  cooperation  with  Dr.  M.  S.  Kharasch  and  was 
published  in  J.  Am.  Chem.  Soc.,  43,  1894  (1921),  in  an  article  by  M.  S.  Kharasch  and 
I.  M.  Jacobsohn. 

2  Dimroth    Ber.,  35,  2853  (1902). 

3vSchoeller,  Schrauth,  and  Liese  (Ber.,  52B,  1777(1919)  apply  the  theory  of  Arm- 
strong for  substitution  in  aromatic  amines  to  mercurization,  the  limitations  of  which 
theory  will  be  pointed  out  later. 


520K- 


isfactorily  orientation  of  other  groups  in  the  case  of  aromatic  amines. 
It  will  be  shown  further,  in  a  condensed  critical  survey  of  the  theories  of 
others,  that  none  of  these  is  completely  satisfactory.  For  example, 
most  of  them  fail  to  account  for  the  fact  that  dimethylaniline  is  mercur- 
ized  readily. 

The  theory  which  the  present  authors  have  been  led  to  adopt  as  a  result 
of  their  extended  experimental  work,  briefly  stated,  is  as  follows.  The 
mercurization  of  an  aromatic  amine  proceeds  in  two  stages :  first,  the  for- 
mation of  an  ammonium  salt  with  the  mercuric  acetate  or  chloride  to  give 
a  compound  of  the  general  type  I. 

Ri  Ri 


•N— R2  XHg— — N 

l\  \ 

X     HgX  II  R2 


This  compound  is  then  rearranged  to  the  more  stable  configuration  hav- 
ing the  mercury  radical  attached  to  carbon,  (Type  II),  the  para  position 
being  usually  favored.4  If  this  position  is  already  occupied,  the  mer- 
cury goes  to  the  oriho  position.  Furthermore,  it  is  only  the  ammonium 
salt  that  undergoes  rearrangement,5  the  instability  of  the  salt  being  due 
to  the  presence  of  an  electropositive  group  or  atom. on  the  amino  nitrogen.6 
This,  it  will  be  noted,  is  the  application  to  mercurization  of  the  theories 
of  substitution  of  Armstrong,7  Bamberger,8  Chattaway9  and  others,  and 
of  the  general  theory  of  catalysis  advanced  by  Stieglitz,10  Acree11  and  others 

4  The  fact  of  rearrangement  may  be  due  to  a  smaller  energy  content  on  the  part 
of  the  rearranged  compound.     This  relationship  was  shown  to  hold  by  Rother  and 
Stoermer  (Ber.,  46,  260  (1913))  for  a  number  of  compounds,  e.  g.,  cinnamic  acid  and  the 
isomeric  allocinnamic  acid. 

5  Acree  and  Johnson,  Am.   Chem.  J.,  38,  265  (1905),  have  demonstrated  that, 
in  the  rearrangement  of  N-chloro-acetanilide,  it  is  the  salt  and  not  the  free  base  that 
rearranges.     They  fail,  however,  to  attach  any  importance  to  the  positive  charge  on 
the  rearranging  group,  a  fact  which  has  already  been   pointed  out  by  Stieglitz   and 
Stagner,  /.  Am.  Chem.  Soc.,  38,  2057  (1916). 

6  Acree  and  Johnson,  Am.  Chem.  J.,  38,  265  (1905),  have  shown  that,  when  N-chloro- 
acetanilide  is  treated  with  hydrogen  bromide,  the  speed  of  the  rearrangement  is  a 
thousand  times  greater  than  when  hydrogen  chloride  is  used,  and  that  the  end  prod- 
uct of  the  rearrangement  is  £-bromo-acetanilide,   instead  of  £-chloro-acetanilide. 

7  Armstrong,  /.  Chem.  Soc.,  51,  258,  583  (1887). 

8  Bamberger,  Ber.,  27,  586  (1894). 

9  Chattaway,  J.  Chem.  Soc.,  75,  1048  (1899). 

10  Stieglitz,  Proc.  Congress  of  Arts  and  Sci.   (St.Louis),  IV,  278(1904);  Am.  Chem. 
J.,  39,  29  (1908). 

»  Acree,  ibid.,  37,  410  (1907). 


that  acid  catalysts  act  through  salt  formation.12  However,  the  theory  ad- 
vanced by  the  present  authors  diverges  from  that  of  Armstrong,  Bamberger, 
and  Chattaway,  and  also  from  recent  theory  of  mercurization  of  Schoeller, 
Schrauth  and  Liese3  in  a  few  very  important  aspects.  The  theories 
advanced  by  the  above  mentioned  authors  assume  that  the  entrance  of  a 
group  into  the  nucleus  of  an  aromatic  amine  is  always  preceded  by  sub- 
stitution on  the  amino  nitrogen,  thus, 


o 


H 
-NH,  +  HONO2     — >     <         >-N-NO2. 


However,  as  an  explanation,  this  is  not  adequate  to  account  for  the  mech- 
anism of  substitution  of  tertiary  amines,  of  the  type  of  dimethyl  aniline 
which  contains  no  replaceable  hydrogen.  Furthermore,  they  do  not  em- 
phasize the  nature  and  importance  of  the  catalysts  used  in  substitution, 
i.  e.,  strong  acids.  That  the  r61e  played  by  acid  catalysts  is  that  of  salt 
formation  has  been  pointed  out  very  clearly  by  Stieglitz10  in  his  work  on 
the  catalysis  of  imido-esters,  as  well  as  by  Acree.11 

We  find  thus,  that  the  previous  hypotheses  have  to  be  modified,  if 
they  are  to  explain  consistently  all  the  facts  of  substitution  without  fur- 
ther assumptions.  The  hypothesis  advanced  by  the  writers  to  explain 
the  mercurization  of  aromatic  amines  lends  itself  admirably  to  this  pur- 
pose. We  shall  now  proceed  to  illustrate  as  briefly  as  possible  the  basis 
for  this  hypothesis  and  then  show  that  it  is  quite  compatible  with  the  oriho 
and  para  orientation  of  other  groups  in  the  case  of  aromatic  amines. 

That  mercury  has  a  great  affinity  for  amino  nitrogen  and  for  carbon 
is  best  illustrated  by  the  readiness  with  which  the  mercury-ammonium 
complexes  are  formed,  and  by  the  great  stability  of  mercury-carbon  com- 
pounds.13 It  is  the  combination  of  this  property  of  mercury  to  form  stable 
nitrogen  and  carbon  compounds,  and  the  relatively  greater  stability  of 
the  latter,  which  enables  us  to  attach  mercury  to  the  carbon  of  the  benzene 
ring  in  the  case  of  aromatic  amines. 

Within  the  scope  of  a  series  of  investigations  being  carried  out  by  the 
one  of  us,  work  was  undertaken  upon  the  mercurization  of  the  N-alkylated 
nitro-anilines.  It  was  found  that  mercurization  does  not  take  place 
when  ^-nitro-dimethylaniline  is  treated  with  mercuric  acetate  in  alco- 
holic solution.  Though  various  experimental  conditions  were  tried,  the 

12  In  this  connection,  the  work  of  Reilly  and  Hickinbotham  (/.  Chem.  Soc.t  117, 
103  (1919))  on  the  rearrangement  of  w-butylaniline  is  quite  significant.    They  found  that 
only  those  salts  which  are  capable  of  combining  with  the  amino  group  effected  the  re- 
arrangement. 

13  The  stability  of  the  mercury-carbon  union  is  a  relative  term.     It  depends  to 
a  large  extent  upon  the  position  of  the  mercury  in  the  molecule  and  upon  the  nature 
of  the  neighboring  groups.     This  will  be  discussed  in  a  later  paper.     See  also  Stieglitz, 
Kharasch,  and  Hanke,  /.  Am.  Chem.  Soc.,  43,  1186  (1921). 


6 

efforts  were  futile.  It  seemed,  however,  in  view  of  the  results  of  an  in- 
vestigation carried  out  with  other  nitro-anilines,14  that  mercurization 
should  take  place  unless  there  was  some  property  of  the  mercurizable 
nitro-anilines  which  was  not  shared  by  the  ^-nitro-dimethylaniline. 
Reference  to  the  literature  at  once  revealed  the  fact  that  p-nitro-dimethyl- 
aniline  is  an  extraordinarily  weak  base.  It  is  precipitated  from  even  cone, 
hydrochloric  acid  solution  as  the  free-  base  instead  of  its  hydrochloride, 
and  it  does  not  combine  with  chloroplatinic  acid.15  Further  reference  to 
the  literature  showed  that  its  oriho  and  meta  isomers  form  salts  more  read- 
ily. An  investigation  of  the  reactions  of  these  isomers  with  mercuric 
acetate  showed  not  only  that  the  reactions  are  completed  within  a  very 
short  time  but  at  a  comparatively  low  temperature.  An  attempt  was  then 
made  to  mercurize  ^-nitro-diethylaniline.  This  met  with  the  same  fail- 
ure as  that  of  the  corresponding  dimethyl  derivative.  That  this  failure 
to  mercurize  is  not  due  simply  to  the  fact  that  the  para  position  is  occu- 
pied was  then  demonstrated  by  the  fact  that  ^-nitro-monomethyl-  and 
^-nitro-mono-ethylanilines  are  mercurized  without  difficulty,  the  mercury 
being  oriented  to  the  position  ortho  to  the  amino  group. 

These  facts,  taken  in  conjunction  with  the  intermediates  already  iso- 
lated16 and  those  obtained  by  Schoeller,  Schrauth  and  Liese,3  the  complex 
salts  of  aromatic  amines  isolated  by  Klein17  and  the  known  general  fact  of 
the  great  affinity  of  mercury  for  an  amino  nitrogen,  led  us  to  adopt  the 
hypothesis  that  mercurization  proceeds  first  by  the  addition  of  the  mercury 
salt  to  the  amino  group,  i.  e.,  to  form  an  ammonium  salt.  This  ammonium 
salt  then  rearranges  to  a  compound  in  which  the  mercuric  radical  is  attached 
to  carbon.4 

From  this  theory  of  the  mechanism  of  mercurization,  one  of  the  most 
logical  deductions  to  be  made  is  that,  of  the  aromatic  amines,  only  those 
which  are  capable  of  forming  salts  will  mercurize.  Among  other  tests,  one 
to  which  this  deduction  has  been  put  was  an  attempt  to  mercurize  tri- 
methyl-phenyl-ammonium  acetate,  a  compound  in  which  the  formation 
of  a  double  salt  with  the  mercuric  acetate  used  is  impossible.  This  com- 
pound was  not  mercurized  although  a  water  suspension  of  dimethyl- 
aniline  mercurizes  within  one  or  two  minutes,  with  great  evolution  of  heat. 

14  Unpublished  work  of  Kharasch,  Lommen,  and  Jacobsohn. 
16  We  found,  however,  that  a  hydrochloride  of  £-nitro-dimethylaniline  could   be 
prepared  by  passing  dry  hydrogen  chloride  into  a  benzene  solution  of  the  base. 

16  Kharasch,  Lommen,  and  Jacobsohn  (unpublished  work)  have  isolated  the  com- 

TT 

pound,'  by  treating  an  alcoholic  solution  of  w-nitroan  iline  with 


02C2H3 
O2N 

an  aqueous  solution  of  mercuric  acetate. 
17  Klein,  Ber.,  11,  743(1778). 


The  theory  here  advanced  as  to  the  mechanism  of  mercurization  of  aro- 
matic amines  adapts  itself  as  already  stated,  quite  readily  to  the  expla- 
nation of  the  orientation  of  other  groups  upon  substitution  in  the  nucleus 
of  aromatic  amines.18  Not  only  does  it  explain  satisfactorily  the  cases  of 
ortho  and  para  substitution  but,  as  will  be  shown  later,  it  explains  also  the 
fact  that  a  mixture  of  all  three  isomers  is  obtained  when  an  aromatic  amine 
is  nitrated  in  cone,  sulfuric  acid  solution,  as  well  as  the  more  recent  ob- 
servations of  Vorlander19  that,  upon  bromination  and  nitration,  the  quater- 
nary ammonium  salts  yield  only  the  meta  derivative. 

To  explain  these  cases  of  meta  substitution,  Vorlander  advances  a  the- 
ory of  the  benzene  nucleus  in  which  he  assumes  that  the  hydrogen  atoms 
in  the  benzene  molecule  have  positive  tensions,20  and  that  it  is  the  tension 
within  the  nucleus  which  determines  the  position  taken  by  the  entering 
substituent.  He  assumes,  further,  that  the  nature  of  the  tension  on  the 
group  already  substituted  in  the  molecule  exerts  an  influence  on  the  arrange- 
ment of  the  tensions  within  the  nucleus.  Thus  for  nitrobenzene  he  as- 
sumes Structure  I. 


I 

while,  for  aniline,  Structure  II  is  assumed.    Further,  substitution  takes  place 
by  absorption  with  the  subsequent  loss  of  a  molecule  of  acid  or  water21  thus : 


Vorlander  makes  the  additional  postulate,  in  order  to  explain  the  cases 
of  meta  substitution  in  aromatic  amines,  that,  upon  salt  formation,  there 
is  a  change  in  the  tension  throughout  the  molecule,  e.  g.,  upon  treating 

18  It  is  self-evident  that  this  theory  is  applicable  also  to  such  rearrangements  as  those 
of  hydrazobenzene,  diazo-aminobenzene,  the  Fischer  and  Hepp,  etc.     It  is  to  be  noted 
that,  in  all  cases,  where  the  rearranging  compound  is  a  weak  base,  the  reaction  must  be 
carried  out  in  the  anhydrous  media  to  insure  salt  formation. 

19  Vorlander,  Ber.,  52B,  263  (1919). 

20  In  order  to  avoid  committing  himself  to  any  theory  as  to  the  nature  of  valence, 
Vorlander  uses  the  term  "tension"  and  denotes  the  kind  of  tension  by  -f-  and  — .     While 
he  does  not  assume  that  they  are  electrical  in  nature,  the  properties  assigned  for  them 
are  such  that,  for  the  purpose  of  discussing  substitution,  there  is  little  distinction  to  be 
made. 

21  It  is  rather  peculiar  that  Vorlander  does  not  take  into  account  the  fact  that  bro- 
mine is  Br  +  — Br~,  unless  by  an  error  in  print,  since  the  existence  of  positive  bromine 
has  been  proved  conclusively.     (W.  A.  Noyes,  J.  Am.   Chem.  Soc.,   23,  460    (1901); 
Stieglitz,  ibid.,  23,  796  (1901) ;  Walden,  Z.  physik.  Chem.,  43,  385  (1903). 


8 
aniline  with  sulfuric  acid,  the  following  change  is  assumed  to  take  place. 


Such  an  assumption  is  entirely  unwarranted.  Not  only  are  there  no  ex- 
perimental facts  upon  which  to  base  such  an  hypothesis,  but  the  assump- 
tion made  involves  an  upheaval  taking  place  within  the  molecule,  as  well 
as  a  change  of  tension  between  the  carbon  and  groups  attached  to  it. 
Such  a  supposition  as  a  change  of  tension  would  also  demand  that,  in  a 
compound  such  as  aniline  nitrate,  analogous  to  aniline  sulfate,  the  ten- 
sion on  the  nitrogen  bound  to  the  phenyl  group  must  be  positive. 


^ON02 


This  compound  should  then,  according  to  the  views  of  Vorlander,  give  a 
meta  derivative  when  dropped  into  cone,  sulfuric  acid.  On  the  contrary, 
however,  it  gives  only  o-  and  p-nitro  derivatives.22  Similarly,  the  ni- 
tration of  aromatic  quaternary  ammonium  compounds  demands,  accord- 
ing to  Vorlander,  that  the  tension  between  the  ammonium  nitrogen  and 
the  carbon  of  the  benzene  nucleus  be  positive  (II).  This  is  hardly  com- 
patible with  the  fact  that  a  water  solution  of  the  hydroxide  of  the  com- 
pound (II)  when  evaporated  gives  a  small  quantity  of  trimethylamine 
and  w-nitrophenol.23  This  theory  must,  therefore,  be  further  modified 
if  it  is  to  be  made  to  fit  all  the  facts  of  substitution  in  aromatic  amines. 

Similarly,  it  has  been  necessary  to  make  additional  postulates  to  all  pre- 
vious theories  in  an  attempt  to  build  a  workable  theory  of  substitution. 
Yet,  with  all  these  postulates,  none  of  the  older  theories  can  be  made  to 
fit  all  the  facts  of  substitution.  However,  no  new  postulates  need  be  made 
to  the  theory  advanced  by  the  present  authors.  Once  it  is  assumed  that 
all  ortho  and  para  substitution  in  the  hydroquinoid  nucleus  of  aromatic 
amines  takes  place  through  intermediate  salt  formation,  it  follows  that, 
when  such  salt  formation  is  impossible,  as  in  the  quaternary  ammonium 
salts,  substitution  must  take  place  in  the  meta  position  or,  as  in  such  spe- 
cial cases  as  that  of  mercurization,  it  is  not  accomplished  at  all. 

Not  only  does  the  theory  advanced  explain  the  case  of  meta  substitu- 
tion in  the  quaternary  ammonium  salts,  but  it  explains  also  the  fact  that 
a  mixture,  of  all  three  isomers  is  obtained  upon  nitration  of  an  aromatic 
amine  in  cone,  sulfuric  acid  solution.  It  explains,  further,  the  fact  that 

22  Bamberger,  Ber.,  28,  400  (1895). 

23  Staedel  and  Bauer,  ibid.,  19,  1939  (1885). 


9 

the  yield  of  the  meta  derivative  increases  with  the  amount  of  sulfuric  acid 
used.  Here  it  will  be  seen  that  an  equilibrium  mixture  of  both  the  amine 
and  the  ammonium  salt  exists  in  such  a  solution.  Therefore,  in  such  a 
mixture  both  types  of  substitution,  that  dependent  upon  intermediate 
compound  formation,  giving  oriho  and  para  derivatives,  and  the  sub- 
stitution of  a  salt  yielding  a  meta  derivative,  are  found.  Again,  as  the 
volume  of  sulfuric  acid  is  increased,  the  equilibrium  will  be  shifted  to  form 
more  of  the  sulfate,  thus  increasing  the  yield  of  the  meta  derivative. 

Furthermore,  the  theory  here  advanced  also  offers  an  explanation  of 
certain  peculiar  facts  of  rearrangement.  For  example,  the  rearrange- 
ment of  /3-phenyl-hydroxylamine24  in  alcoholic  solution  with  hydrogen 
chloride  as  catalyst,  gives  not  only  £-amino  phenetole  but  also  £-chloro- 
aniline,  the  more  strongly  electro  positive  chlorine  atom  rearranging. 
The  theory  advanced  predicts  that  N -substituted  aromatic  amines, 
when  treated  with  a  catalyst  capable  of  being  oxidized  by  the  group  al- 
ready substituted  in  the  molecule  will  yield  a  derivative  having  the  more 
strongly  electro  positive  group  in  the  para  position. 

It  will  be  seen,  therefore,  that  the  present  theory  explains  from  a  sin- 
gle standpoint  the  rearrangement  and  substitution  in  the  case  of  aromatic 
amines,  without  the  necessity  of  any  additional  postulates.  It  is  also 
far  more  adequate  for  the  explanation  of  these  facts  and  furnishes  a  more 
workable  hypothesis  than  any  of  the  other  theories  of  substitution. 

Experimental  Part. 
Method  used  for  Mercurization. 

The  method  used  for  the  preparation  of  the  compounds  herein  described 
is,  briefly,  as  follows.  One  mol  of  the  compound  to  be  mercurized  was 
dissolved  in  a  small  volume  of  alcohol  and  boiled  with  an  aqueous  solution 
containing  0 . 9  mol  of  mercuric  acetate,  until  a  test  portion  gave  no  black 
precipitate  of  mercuric  sulfide  when  treated  with  ammonium  sulfide. 
This  reaction  mixture  was  filtered  hot.  Upon  cooling;  the  acetate  of  the 
mercurized  compound  crystallized  from  the  solution. 

The  filtrate  from  the  above  was  treated  with  an  aqueous  solution  of 
sodium  chloride,  whereupon  the  chloride  of  the  mercury  compound  soon 
precipitated.  The  total  yield  of  mercurized  product  calculated  upon 
the  basis  of  the  mercuric  acetate  used,  was  almost  quantitative. 

An  Attempt  to  Mercurize  £-Nitro-dimethylaniline  and  £-Nitro-diethylaniline. — 
As  stated  in  the  theoretical  part,  several  attempts  were  made  to  mercurize  p-nitro- 
dimethylaniline,  all  of  which  met  with  failure.  The  method  above  outlined  was  used, 
as  well  as  several  other  methods,  none  of  which  yielded  a  mercurized  product.  Similarly, 
attempts  to  mercurize  />-nitro-diethylaniline  were  without  success. 

o-Nitro-/)-Acetoxymercuri-dimethylaniline,  (C6H3(l)N(CH3)2(2)NO2(4)HgO2C2H,.) 
—This  compound  was  prepared  from  o-nitro-dimethylaniline  and  mercuric  acetate. 

24  See,  however,  Stieglitz,  Am.  Chem.  /.,  46,  327  (1911 


10 

The  reaction  was  completed  after  half  an  hour's  boiling.  The  reaction  mixture 
was  filtered  hot  in  order  to  remove  the  small  amount  of  mercurous  acetate  formed 
in  the  reaction.  It  was  then  cooled  and  the  precipitate  collected  on  a  filter.  The 
precipitate  was  then  washed  with  alcohol,  and  dried  to  constant  weight  in  vacuo  over 
sulfuric  acid. 

Analyses.  Subs.,  0.2759:  dry  N2,  16.20  cc.  (22°  and  741  mm.).  Subs.,  0.2604: 
HgS,  0.1427.  Calc.  for  Ci0Hi2O4N2Hg;  N,  6.61;  Hg,  47.23.  Found:  N,  6.63; 
Hg,  47.26. 

The  compound  thus  obtained  is  bright  yellow;  m.  p.  160°.  It  is  crystalline,  and  is 
soluble  in  the  common  organic  solvents. 

o-Nitro-/>-Chloromercuri-dimethylaniline.  (C«H«(l)N(CH«)(2)NOs(4)HgCI.HjO).— ' 
This  compound  was  washed  well  with  water  to  remove  sodium  chloride  and 
finally  with  alcohol,  and  dried  in  vacuo  over  sulfuric  acid  to  constant  weight. 

Analyses.  Subs.,  0.2635:  dry  N2,  15.60  cc.  (21.5°  and  741  mm.).  Subs.,  0.3233: 
AgCl,  0.1096.  Calc.  for  C8HnO3N2HgCl :  N,  6.69;  Cl,  8.46.  Found.  N,  6.71; 
Cl,  8.38. 

The  substance  is  red  and  amorphous.  It  is  soluble  in  acetone  and  in  boiling  alco- 
hol. It  melts  at  185°,  with  decomposition. 

w-Nitro  -  p  -  Acetoxymercuri  -  dimethylaniline,  (C6H8(l)N(CH3)2(3)NO2(4)HgO2- 
C2H3). — This  preparation  was  obtained  upon  treating  w-nitro-dimethylaniline  with 
mercuric  acetate.  A  half  hour's  boiling  was  sufficient  to  carry  the  reaction  to  com- 
pletion. For  analysis,  the  compound  was  dried  to  constant  weight  over  sulfuric  acid. 

Analyses.  Subs.,  0.2924:  dry  N2,  17.05  cc.  (20°  and  734  mm.).  Subs.,  0.2940: 
HgS,  0.1610.  Calc.  for  Ci0Hi204N2Hg:N,  6.61;. Hg,  47.23.  Found:  N,  6.56;  Hg, 
47.23. 

The  compound  is  obtained  in  the  form  of  brilliant  orange  needles.  It  is  soluble 
in  the  common  organic  solvents;  m.  p.  140°. 

w-Nitro  -  p  -  Chloromercuri-dimethylaniline,  (C6H3(l)N(CH3)2(3)NO2(4)HgCl)  .— 
This  compound  was  obtained  from  the  filtrate  of  the  preceding  preparation. 

Analysis.  Subs.,  0.3438:  AgCl,  0.1237.  Calc.  for  C8H9O2N2HgCl:  Cl,  8.84. 
Found:  8.90. 

The  compound  is  red  and  amorphous.  It  is  soluble  in  acetone  and  in  boiling  alco- 
hol. It  melts  at  220°,  with  decomposition. 

^-Nitro-o-Acetoxymercuri-monomethylaniline,  (C6H3(l)NH.CH3(4)NO2(2)HgO2- 
C2H3). — This  compound  was  prepared  from  £-nitro-methylaniline  and  mercuric  acetate. 
The  product  obtained  was  extracted  with  ether  in  order  to  remove  unchanged  ^-nitro- 
methylaniline,  and  the  residue  was  recrystallized  from  alcohol.  A  dark  red  solid 
remained  which  was  insoluble  in  alcohol,  but  the  quantity  was  too  small  to  be  analyzed. 

Analyses.  Subs.,  0.2585:  dry  N2,  15.6cc.  (21°  and  736  mm.).  Subs.,  0.2981: 
HgS,  0.1673.  Calc.  for  C9H10O4N2Hg:  N,  6.84;  Hg,  48.82.  Found:  N,  6.79; 
Hg,  48.38. 

The  compound  forms  small  yellow  crystals  melting  at  197°  with  decomposition. 
It  is  soluble  in  acetone  and  in  hot  alcohol  to  which  a  few  drops  of  glacial  acetic  acid 
have  been  added.  When  treated  with  a  cone,  potassium  hydroxide  solution,  a  brick- 
red  compound  is  formed.  Upon  dilution,  the  compound  again  becomes  yellow. 

p-Ni  tro-o-Chloromercuri  -  monomethylaniline,  (C6H3  ( 1 )  N .  H .  CH3  (4)  NO2  (2)  HgCl- 
H2O). — This  compound  is  obtained  from  the  filtrate  of  the  preceding  compound. 

Analysis.  Subs.,  0.2972:  AgCl,  0.1036.  Calc.  for  C7H9O3N2HgCl:  Cl,  8.75. 
Found:  8.62. 

The  compound  is  yellow  and  crystalline.  It  is  soluble  in  acetone  and  in  boiling 
alcohol.  It  melts  at  215°,  with  decomposition. 


11 

The  position  of  the  mercury  in  this  compound  was  determined  by  the  method  of 
Dimroth.26  The  acetate  was  treated  with  two  equivalents  of  a  solution  of  potassium 
perbromide.  The  product  was  then  extracted  with  ether  and  the  extract  purified  from 
alcohol;  m.  p.  112-113°.  When  mixed  with  4-nitro-2,6-dibromo-monomethylaniline, 
prepared  by  the  method  of  Blanksma,26  the  melting  point  was  not  lowered.  The  use 
of  only  one  molecule  of  the  bromine  in  solution  yielded  no  definite  compound.  Since  the 
position  could  not  be  thus  in  dispute  the  dibromo  derivative  was  therefore  isolated. 

/?-Nitro-0-Acetoxymercuri-mono-ethylaniline,  (C6H8(l)N.H.C2H5(4)NO2(2)Hg.O2- 
C2H3). — This  compound  was  prepared  from  £-nitro-mono-ethylaniline,  and  was  purified 
from  the  unchanged  raw  material  by  recrystallization  from  alcohol. 

Analyses.  Subs.,  0.2641:  dry  N2,  15.7  cc.  (24.5°  and  731  mm.).  Subs.,  0.3480; 
HgS,  0.1912.  Calc.,  for  CioHi2O4N2Hg:  N,  6.61;  Hg,  47.23.  Found:  N,  6.56; 
Hg,  47.17. 

It  crystallizes  from  alcohol  in  small  yellow  crystals;  m.  p.  183°.  It  is  also  soluble 
in  acetone.  When  treated  with  cone,  potassium  hydroxide  solution,  a  brick-red 
compound  is  obtained.  Dilution  of  the  solution  restored  the  original  yellow  color. 

/>-Nitro-0-Chloromercuri-mono-ethylaniline,  (C6H3(l)N.H.C2H8(4)NO2(2)HgCl- 
H2Q). — The  compound  was  prepared  in  the  usual  manner.  It  is  obtained  in  the  form 
of  an  amorphous  yellow  solid;  m.p.  218°,  with  decomposition.  For  analysis  it  was 
dried  to  constant  weight  over  sulfuric  acid. 

Analysis.  Subs.,  0.4544:  AgCl,  0.1573.  Calc.  for  CgHnOaNaHgCl:  Cl,  8.46; 
Found:  8.56. 

It  is  soluble  in  acetone  and  in  hot  alcohol. 

The  position  of  the  mercury  in  this  compound  was  determined  by  the  method 
used  above  for  the  corresponding  methyl  derivative.  The  melting  point  of  the  4-nitro- 
2,6-dibromo-ethylaniline  thus  obtained  was  68-71°.  The  melting  point  was  not  low- 
ered when  a  mixture  of  the  compound  with  known  4-nitro-2,6-dibromo-ethylaniline 
was  used. 

£-Nitro-0-Bromo-mono-ethylamline,  (C6H3(l)N.H.C2H5Br(4)NO2) . — This  com- 
pound was  prepared  by  the  addition  of  a  solution  of  bromine  in  glacial  acetic  acid 
to  a  solution  of  an  equivalent  portion  of  £-nitro-mono-ethylaniline  in  the  same  solvent. 
After  standing  for  about  half  an  hour,  -the  reaction  mixture  was  diluted  with  water, 
and  the  precipitated  compound  collected  on  a  filter.  It  was  washed  with  water  and 
a  little  alcohol.  After  crystallization  from  alcohol,  the  compound  was  dried  to  con- 
stant weight  in  vacua.  Yield,  90%. 

Analysis.  Subs.,  0.2704:  dry  N2,  26.50  cc.  (17°  and  750  mm.).  Calc.  for 
C8H902N2Br:  N,  11.44.  Found:  11.39. 

The  compound  crystallized  from  alcohol  in  beautiful  long  yellow  prisms  which  are 
highly  refractive;  m.p.  65°  to  66°.  It  is  insoluble  in  water  but  soluble  in  all  common 
organic  solvents. 

When  an  alcoholic  solution  of  the  compound  is  treated  with  cone,  potassium  hy- 
droxide solution,  the  alcoholic  layer  assumes  a  red  color.  Upon  evaporation  of  the 
alcohol,  or  upon  dilution  with  water,  the  yellow  compound  is  again  obtained. 

£-Nitro-0-Dibromo-mono-ethylaniline,  (C«Ht(l)N.H.CtHs(2>6)Br«(4)NOi).— Thia 
compound  was  prepared  in  the  same  manner  as  the  above  monobromo  derivative, 
in  this  case,  with  two  mols  of  bromine.  For  analysis  the  compound  was  crystallized 
from  alcohol.  Yield,  90%. 

Analysis.  Subs.,  0.2761 :  dry  N2,  21.2  cc.  (21°  and  744  mm.).  Calc.  for  C8H8O2N2- 
Br2:  N,  8.68.  Found:  N,  8.74. 


25  Dimroth,  Ber.,  35,  2033  (1902). 

26  Blanksma,  Rec.  trav.  chem.,  31,  271  (1902). 


12 

This  compound  crystallized  from  alcohol  in  small  yellow  needles;  m.p.  75-76°. 
It  is  insoluble  in  water,  but  soluble  in  all  common  organic  solvents. 

Upon  treatment  with  a  cone,  potassium  hydroxide  solution,  an  alcoholic  solution 
of  the  compound  turns  red.  If  the  alcohol  is  evaporated,  or  the  solution  diluted 
with  water,  the  color  is  restored  to  the  original  yellow. 

An  Attempt  to  Mercurize  Trimethyl-phenyl-ammonium  Acetate. — A  solution  of 
0.5  mol  of  mercuric  acetate  was  added  to  a  solution  of  trimethyl-phenyl-ammonium 
acetate.  Even  after  standing  for  two  months  at  room  temperature,  no  mercurized 
product  could  be  isolated.  The  solution  gave  a  heavy  precipitate  of  mercuric  sulfide 
when  treated  with  hydrogen  sulfide. 

Upon  boiling  another  portion  of  the  solution  for  24  hours,  no  change  was  observed. 
A  heavy  precipitate  of  mercuric  sulfide  was  again  obtained  upon  treatment  with  hydro- 
gen sulfide. 

Summary. 

1.  A  theory  of  the  mercurization  of  aromatic  amines  has  been  advanced, 
postulating  that  mercurization  is  preceded  by  addition  of  a  mercuric  salt 
to  the  amino  nitrogen,  with  the  subsequent  rearrangement  of  the  mer- 
cury to  the  ortho  or  para  position.     This  theory,  without  any  additional 
postulates,  has  been  shown  to  apply  equally  well  to  the  introduction  of 
other  groups  in  the  benzene  nucleus  in  the  case  of  aromatic  amines. 

2.  This  theory  has  been  shown  to  apply  also  to  rearrangements  such  as 
that  of  Fischer  and  Hepp,  the  nitro-amines,  sulfamic  acids,  etc. 

3.  The  limitations  to  other  theories  of  substitution  have  been  pointed 
out. 

4.  The  preparation  of  mercury  derivatives  of  £>-nitro-methylaniline, 
^-nitro-ethylaniline,  o-nitro-dimethylaniline,  and  m-nitro-dimethylaniline, 
and   the   preparation   of   0-bromo   and   0,<?-dibromo-£-nitro-ethylanilines 
have  been  described. 


13 


A  STUDY  OF  THE  NITRANILINES.1     DETERMINATION 

OF  THE  POSITION  OF  THE  MERCURY  IN  THE 

MERCURIZED  NITRANILINES. 

The  purpose  of  this  investigation  was  to  determine  the  positions  which 
mercury  takes  upon  introduction  into  the  benzene  nucleus  of  the  three 
isomeric  nitranilines.  It  was  found  that  the  positions  taken  by  the 
mercury  in  the  nitro-anilines  is  always  ortho  or  para  or  ortho-para  to 
the  amino  group.2  This  was  established  by  preparing  the  acetyl  deriva- 
tives of  the  various  mercurized  products,  and  subsequent  replacement 
by  bromine.  The  bromo  derivatives  were  then  compared  with  the  re- 
spective synthetic  products,  prepared  by  other  methods,  and  were  found 
not  to  depress  their  melting  points. 

It  was  found,  in  all  cases,  that  the  positions  taken  were  in  perfect 
agreement  with  those  demanded  by  the  theory  outlined  in  the  preceding 
paper. 

o-Acetoxymercuri-acetyl-^-nitro-aniline.  [C6H3(l)NH-(CO-CH3)(4)NO2(2)HgO.- 
OC2H3]. — To  prepare  this  compound  4  g.  of  0-acetoxymercuri-£-nitro-aniline  was  boiled 
under  a  reflux  condenser  with  10  cc.  of  acetic  anhydride  and  30  cc.  of  ethyl  acetate. 
After  a  short  time  the  solid  was  completely  dissolved.  The  solution  was  then  filtered 
hot,  and  upon  cooling  a  white  crystalline  product  separated.  This  was  collected  on  a 
filter  and  washed  with  alcohol.  Yield,  50%. 

The  compound  is  white  and  crystalline.     It  is  soluble  in  ethyl  acetate.     With 
sodium  hydroxide  it  gives  no  color  change. 
Determination  of  the  Position  of  the  Mercury  in  the  Mercurized  £-Nitro-aniline 

The  position  of  the  mercury  in  the  mono-mercury-substituted  p-nitro-aniline  was 
determined  in  the  following  manner.  One  mol  of  o-acetoxymercuri-acetyl-p-nitro- 
aniline  was  treated  with  1  mol  of  potassium  perbromide  solution  and  the  whole  shaken 
until  the  color  of  the  bromine  had  disappeared.  The  solid  product  of  the  reaction 
was  collected  on  a  filter  and  washed  with  water.  It  was  then  extracted  with  ether, 
the  ethereal  extract  was  evaporated  to  dryness,  and  the  residue  was  recrystallized 
from  hot  water;  m.  p.  130°.  When  mixed  with  £-nitro-o-bromo-acetanilide  prepared 
by  synthetic  methods,  the  melting  point  was  not  lowered.  The  position  of  the 
mercury  is  thus  established  as  ortho  to  the  amino  group. 

To  determine  the  position  of  the  mercury  in  the  dimercury-substituted  £-nitro- 
aniline  the  compound  was  first  acetylated,  in  ethyl  acetate  suspension  with  acetic 


1  This  work  was  carried  out  in  cooperation  with  Dr.  M.  S.  Kharasch  and  was  in- 
cluded in  a  paper  published  in  /.  Am.  Chem.  Soc.  44,  793  (1922),  by  M.  S.  Kharasch, 
F.  W.  M.  Lommen,  and  I.  M,  Jacobsohn. 

2  It  is  of  considerable  interest,  in  this  connection,  that  in  the  case  of  the  dimercury 
compound  of  w-nitro-aniline  the  positions  taken  by  the  mercury  are  2,4  (NHj  =  l, 

=  3)  and  not  4,6  as  one  might  expect. 


14 

anhydride.  The  reaction  was  considered  complete  when  the  whole  became  almost 
white.3  The  acetylated  compound  thus  obtained  was  treated  with  two  mols  of  potas- 
sium perbromide  in  a  manner  similar  to  that  used  for  the  monomercury  substi- 
tuted derivative.  A  product  was  obtained  which  melted  at  225-227°.  When  mixed 
with  4-nitro-2,6-dibromo-acetanilide  the  melting  point  was  not  lowered.  The  position 
of  the  mercury  is  thus  established  as  being  in  the  2,6  positions  (NH2  =  1). 

£-Acetoxvmercuri-diacetyl-0-nitro-aniline,     [C0H2(l)N(CO-CH3)2(2)NO2(4)HgO- 
OC2HS]. — This  compound  was  prepared  from^-acetoxymercuri-o-nitro-aniline,  using  the 
same  procedure  as  that  already  used  for  the  preparation  of  the  corresponding  p-n\tro- 
aniline  derivative.      The   reaction    in  this  case  was  found  to  take  place  much  more 
slowly.     For  analysis  the  compound  was  dried  in  vacua  to  constant  weight. 

Analysis.  Subs.,  0.2654:  13.8  cc.  of  dry  N2  (22°  and  737.0  mm.).  Calc.  for  Ci2Hu- 
O6N2Hg:  N,  5.84.  Found:  5.87. 

The  compound  is  of  a  straw-yellow  color.  It  is  soluble  in  sodium  hydroxide  solution 
imparting  to  the  solution  a  yellow  coloration.  M.  p.  194°  with  decomposition. 

£-Acetoxymercuri-acetyl-0-nitro-aniline,  [C6H2(1)N  -H  -CO  -CH3)  (2)NO2(4)HgO- 
OC2H3]. — To  prepare  this  compound,  a  water  suspension  of  ^-acetoxymercuri- 
diacetyl-0-nitro-aniline  was  treated  with  a  dilute  solution  of  sodium  hydroxide.  The 
compound  dissolved,  giving  the  solution  a  yellow  color.  The  solution  was  then  filtered 
immediately  into  dil.  acetic  acid.  A  yellow  crystalline  precipitate  formed  immediately. 
This  was  collected  on  a  filter  and  washed  with  water  and  alcohol.  For  analysis  the 
compound  was  dried  in  vacua  over  sulfuric  acid  to  constant  weight. 

Analysis.  Subs.,  0.2835:  16.42  cc.  of  dry  N2  (20°  and  737.2  mm.).  Calc.  for 
CioH1005N2Hg:  N,  6.40.  Found:  6.55. 

The  compound  is  yellow  and  crystalline.  It  dissolves  in  sodium  hydroxide,  forming 
a  yellow  solution.  After  a  short  time  this  solution  yields  a  red  precipitate,  further 
de-acetylation  having  taken  place..  It  melts  with  decompositon  at  194°. 

Determination  of  the  Position  of  the  Mercury  in  the  Mercurized  o-Nitro-aniline  De- 
rivative 

To  determine  the  position  of  the  mercury  in  the  mercury  derivative,  the  diacetyl 
compound  was  treated  with  potassium  perbromide  in  the  same  manner  as  already  de- 
scribed for  the  corresponding  para  compound.  A  lemon  colored  compound  was  obtained 
which,  when  recrystallized  from  water,  melts  at  104°.  When  mixed  with  some  known 
0-nitro-/>-bromo-acetanilide  the  melting  point  was  not  lowered.  The  mercury  is  shown 
thus  to  be  in  the  position  para  with  respect  to  the  amino  group. 

^-Acetoxymercuri-acetyl-w-nitro-aniline,  [C6H8(1)NH-  (COCH3)  (3)NO2(4)HgO  •- 
OC2H3]. — This  compound  was  prepared  from  £-acetoxymercuri-w-nitro-aniline  in  the 
same  manner  as  that  described  for  the  p-nitro-aniline  derivative  above.  For  analysis 
it  was  dried  in  vacuo  over  sulfuric  acid  to  constant  weight. 

Analysis.  Subs.,  0.2522:  14.24  cc.  of  dry  N2  (18°  and  739.5  mm.).  Calc.  for 
Ci0H1005N2Hg:  N,  6.40.  Found:  6.45. 

This  compound  is  white.     It  melts  with  decomposition  at  230  °. 

Determination  of  the  Position  of  the  Mercury  in  the  Mercurized  w-Nitro-aniline 

The  method  of  procedure  used  in  determining  the  position  of  the  m-nitro-aniline 
derivative?  was  similar  to  that  used  for  the  para  compound.  The  compound  obtained 

3  The  compound  thus  obtained  was  insoluble  in  the  common  organic  solvents  and, 
owing  to  the  presence  of  an  appreciable  quantity  of  metallic  mercury  formed  in  the 
course  of  the  acetylation,  was  not  analyzed. 


15 

when  recrystallized  from  water  melted  at  135-139°.  When  mixed  with  some  known 
£-bromo-w-nitro-acetanilide  the  melting  point  was  not  lowered.  The  position  of  the 
mercury  is  thus  shown  to  be  para  to  the  amino  group. 

To  determine  the  position  of  the  mercury  in  the  dimercury-substituted  w-nitro- 
aniline,  the  latter  compound  was  suspended  in  ethyl  acetate  and  boiled  under  a  reflux 
condenser  with  acetic  anhydride  until  the  whole  became  white.4  The  icetyl  derivative 
thus  prepared  was  treated  with  2  mols  of  potassium  perbromide,  in  the  manner  previously 
described.  The  product  obtained  was  then  filtered,  dried  and  extracted  with  ether. 
The  ethereal  extract  was  evaporated  to  dryness,  leaving  a  residue  of  melting  point 
141-146  °.  Upon  recrystallization  from  50%  alcohol  it  melted  at  150  °.  When  mixed  with 
known  2,4-dibromo-3-nitro-acetanilide  the  melting  point  was  not  lowered.  The  com- 
pound was  then  de-acetylated  with  cone,  sulfuric  acid  at  120°.  Upon  dilution  of  this 
reaction  mixture  with  water,  a  yellow  product  melting  at  84-87°  was  obtained.  Upon 
recrystallization  from  50%  alcohol,  a  product  melting  at  89°  was  obtained.  When 
mixed  with  known  2,4-dibromo-3-nitro-aniline,  the  melting  point  was  not  lowered. 
This  identifies  the  position  of  the  mercury  as  being  2,4  with  respect  to  the  amino  group 
(N02=3). 

4  In  the  course  of  the  reaction,  an  appreciable  amount  of  metallic  mercury  was 
formed.  Since  the  compound  thus  obtained  is  insoluble  in  the  common  organic  solvents, 
it  could  not  be  purified,  and  therefore  was  not  analyzed. 


In  conclusion,  the  writer  takes  pleasure  in  acknowledging  gratefully  his 
appreciation  of  the  sympathetic  encouragement  and  personal  kindness 
which  Dr.  M.  S.  Kharasch  has  shown  him  in  the  guidance  of  his  work. 


FINE  OF  25  CENTS 

. 

BOOK   ON   THE 

SS 

OVERDUE. 


-       13 — 


LD  21-100m-8,'34 


Syracuse,  N.  Y. 

PAT.  JAN  21,  1908 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


